[awj]

Phrasing it as "solving the biggest problem" is a little ... grandiose, though. How can you even quantify such a thing? Why should I swing for that fence when the problem is likely "bigger" for me because I am abnormally impaired at dealing with it?

I think there's an ad-hoc, informally specified set of standards for when a problem is "big enough" that people will pay to have it solved. What you're looking for is something within that range where you can out-executing the competition. Searching for "the biggest problem" oversatisfies the first half of that proposition at the expense of the second.

All that said, I find little inconvenience in the current fast food ordering process. Often there is a language barrier, but a combination of numbered meals and ambivalence towards picking off what I don't want solves that issue.

Possibly the restaurants could find value in making the experience "good enough" to keep me from going down the street and paying more at $fancy_restaurant where ordering is (relatively) hassle-free? I'm not convinced that can be done via phone in the lowest-common-denominator fashion of fast food.